Can you use a Bear Can as windscreen for a stove?

[Jon Fong / Flat Cat Gear]

In the wind, a number of people claim that a tree or rock will work well as a wind block/screen.  I decided to test this theory out. Instead of a tree, I chose a Garcia Bear can as I often bring one on trips to the Sierra.  I selected the BRS 3000t as it seems to be the darling of a number of UL backpackers.  The plan was to position theBear Canister at three different distances from the gas canister (1″, 6″ and 12″) and the wind tunnel was set for 8 mph.

Results: starting with 500 ml of 68 F water @ the 1″ distance, I stopped the test after 15 minutes as the water only reached 187 F.  The stove consumed 21.4 g of fuel and the linear projection was it would require about 26 g to reach a full boil.  Again, this was a 1 inch distance between the fuel canister and get Bear can.  I am planning on re-testing this with a log and maybe a rock.

[Terran Terran]

What if you go 5 inches? Or lay it on it’s side? https://www.tec-science.com/mechanics/gases-and-liquids/flow-separation-boundary-layer-separation/

[Axel J]

When I first read the title of this post, I was visualizing putting your stove in an emptied bear canister, not beside it.

[Bill Budney]

Yeah, a bear canister is neither a rock nor a log. Not even a tree stump. It’s a smooth cylinder that acts more like a wing than a windscreen.

There are often natural windbreaks in the environment; most are fairly obvious.

The reason we carry a windscreen is for those times when natural windbreaks (or a well-ventilated tent vestibule) are not available.

 

[DWR D]

I once used rolled up my closed cell foam pad for a wind break… worked great on the snow where too much heat was being lost… foam pad kept the heat in and dinner got warm fast…

[MJ H]

What if you put the stove in the canister and drilled holes along the bottom so it could get air?

[Bill Budney]

Uh oh. Please don’t ask me to drill holes in my expensive bear canister! :)

[John S.]

I use my closed cell foam sleeping pad for a windscreen.

[Ryan Jordan]

Bear cans, “small” natural wind breaks – none of these make great windscreens.

Just returned from a trip in the Never Summer Wilderness, and we had a bit of wind at our high camps. Wanting to shave 1.5 oz, I opted for a tiny stove instead of my usual (MSR Pocket Rocket Deluxe). I tried to find and build windbreaks like this:

…but it wasn’t enough, and I burned through fuel at 2X the rate compared to using my PRD. As Jon’s data and our Stovebench data show, it doesn’t take much wind to completely destroy the effectiveness of a canister stove that has a small burner or no windbreak lip on the burner.

I’ve tried the sleeping pad thing, which is fine, but you have to hold it in place in all but the slightest breeze, or secure it with rocks, etc.

The only natural wind break I’d say is effective is to get on the leeward side of a cliff so you absolutely feel no wind where you are cooking. Even on the leeward side of big boulders, especially in alpine areas, airflow is going to be turbulent behind the boulder and swirl around. In our campsite where the photo above was taken, we had wind constantly coming at us from multiple directions, it was swirling in the alpine cirque where we were camped.

[DWR D]

“What if you put the stove in the canister and drilled holes along the bottom so it could get air?”

That would make it a very heavy windscreen and ruin it as a bear can… and probably no longer a legal bear can where required. (there is a reason that bear cans are round… holes would give bear claws a spot to rip at)

 

[jscott]

Geeze :Louise: I use the outer part of a Caldera cone as a windscreen. It wraps–safely!! for one person use, at least–around my pot and canister, not tight, but at a safe distance. I can test the heat on the canister with a quick touch of my finger, but it never heats up. Far, far better than any of the options here./ Of course, placing all this behind a convenient set of rocks or tree stumps helps too.

Weight? about an ounce.

You don’t have to use this contraption. There are plenty of other dedicated windscreens available. That weigh in at an ounce or two. I’m all for using items double duty. This seems….

[Glen L]

We have built dozens of stone windbreaks like Ryan’s example mostly with slabs of sandstone, very quick and easy. They work well but nothing I’ve experienced works as well for a top stove as the creations like Jon Fong makes or like the similar windscreen we use for the Gigapower. This uses 5 g of fuel to boil 500 ml, protects the flame and focuses heat. Jon’s are less weight but I don’t see one for the Gigapower.

[George W]

A bear canister makes a better wind block if you lay it down on its side. Not always great, but far better than nothing. And you typically have something else with you, or in your surroundings to add to it.

[Jerry Adams]

I read somewhere that if you pick up rocks off the ground and use them, that can disturb critters living underneath the rock.

I’m not ready to totally give that up.  If I start to lift a rock and there are a lot of critters I’ll probably carefully set it back.

[Ryan Jordan]

Good point Jerry. The other thing that bothers me about extracting rocks that are already partially embedded in the ground is that they leave unsightly holes. So I try to find rocks that are just laying around on slabs, etc., and not partially buried. In a perfect world, those do exist and are readily available!

[Glen L]

“I read somewhere that if you pick up rocks off the ground and use them, that can disturb critters living underneath the rock.”

Yes! Lol

We are usually careful and don’t disturb the natural environment but some sandstone slabs are kind of stacked on top so nothing underneath. Once we had hiked cross country to White Pocket an area close to The Wave. We had to go as minimally as possible because we had to carry a lot of water. So we just lay our bags on a ground tarp cowboy style. It was windy so in weighing down the tarp with rocks there was a huge green scorpion so I gently lay it back down. I didn’t feel anything walking across my face so it must have stayed there. Same thing happened in the Eagletail wilderness west of the Phoenix valley when I moved a piece of wood someone obviously had left behind, the place where we car camped on our way back from So Cal. There was a sidewinder rattlesnake under it, you know the ones with extremely potent venom. Got a great photo and carefully place the wood gently down. It was gone in the morning. I think we’ve seen various colored scorpions at every elevation up into the 7000s at most everywhere we’ve put up a tent. Arachnids are amazing.

 

its best to leave things as much alone as possible.

[jscott]

“In a perfect world, those do exist and are readily available!”

Well, that pretty much makes the Sierra a perfect world! You can’t throw a stone without…well hitting another one. And at elevation they’re just lying on top of a bit of sand and, yep, more granite. So it’s easy enough to build a wind screen, generally, or find rocks to hold tent stakes, if the latter won’t pound into the ground because there’s no soil. it’s rock. I think the only critters are microbial in these rocks. If that. But generally, it’s also easy to find already downed trees or large erratic boulders or smaller rocks already in place to use as a wind screen. No need to haul stones–except small rocks to use as stake anchors, at times. Often these are just readily available.

In the PNW, it’s another matter, where hiking in forests and deeper soils is more common. I wouldn’t want to disturb that environment by ripping up rocks embedded in deeper soils.

 

“arachnids are amazing.” That’s one way to put it.

[Adrian Griffin]

Moving around rocks makes the place start to look beat-up and used. Make yourself a windshield with a piece of titanium from Ali Express. Or get one of Jon’s.

Here’s mine. It’s held on with hooks made from paper clips. The reflector, made from a foil pie plate, goes below the burner. I needed to make my own because my pots are wider than the pot arms on the stove. But Jon’s Flat Cat is a less fiddly solution if your pot will fit.

Hook detail

[Thom]

Ok

[Thom]

[Terran Terran]

In most cases, I think I’d rather carry a windscreen than move around a bunch of rock at the end of the day. 

[Jon Fong / Flat Cat Gear]

OK, I decided to re-run the experiment using a log. The wood was 12” in the largest diameter and the experiment was run with the log 1” and 6” away from the canister. Again I used the BRS 3000t stove to heat 500 ml of 68F water in an 8-mph wind. Here are the results.

@ 1”, the stove consumed 14.3 g of fuel and it took 6:49 to reach a boil
@ 6” the stove consumed 31.7 g of fuel and it took 11:15 to boil

And for grins, I also tested 7” log
@ 1” the stove consumed 23.3g of fuel and took 9:48 to reach a boil

So, a tree can work as a wind block if you can find a level spot right next to the trunk that is at least 12: in diameter. My 2 cents.

[Dan]

I found this at a recent campsite in the Mt Zirkel wilderness (I owe a trip report). I had a caldera cone/kojin setup so I didn’t use it. But nice work, don’t you think?

TBH, I don’t really like to find things like this in the wilderness, even at an established campsite. But if it’s there, I would use it.

[Dan]

As for the original bear canister idea, it might work better to lay the canister on its side, so the shape will be less streamlined. Still … I sense it’s not the best option.

[Dustin V]

I wouldn’t bother to haul a tree trunk over for just a couple minutes cooking. My trunk worked okay as a wind break last weekend. It’s getting a little better every year.  :-/

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